Children gave us significant purchases in retirement (5)
I believe the answer is:
issue
'children' is the definition.
(issue can mean someone's offspring)
'gave us significant purchases in retirement' is the wordplay.
'purchases' indicates a hidden word (I've seen 'purchasing' mean this).
'in retirement' shows that the letters should be reversed in order (retire can mean to go back or backwards).
'eussi' can be found hidden inside 'gave us significant'.
'eussi' in reverse letter order is 'ISSUE'.
(Other definitions for issue that I've seen before include "Matter of contention" , "Publish - put into circulation" , "Children; topic for debate" , "Give or send out" , "Subject of debate" .)